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NASA Will Man Destruct Switch Just In Case

Posted by CmdrTaco on from the explosions-are-cool dept.

Ant writes "Popular Mechanics reports if the looming Discovery mission or any other between now and the spacecraft's retirement loses control, National Aeronautics and Space Administration (NASA) is prepared to ditch it in the Atlantic ocean — or blow it up. The article also shows complete no-fly-zone maps and a photograph of the switch."

4 of 196 comments (clear)

  1. Re:Four Buttons? by Anonymous Coward · · Score: 5, Informative

    The "Test" button probably checks the detonation circuits, WITHOUT igniting the actual charges. And the "Safe" button is probably for permanently disarming the charges once the shuttle's in orbit.

  2. Already been used by camperdave · · Score: 5, Informative
    Not only are the destruct switches active during each and every launch, they have actually been used on one particular launch. When Challenger's external fuel tank blew up, destroying the shuttle, the solid rocket boosters started to fly out of control.

    At T+110.250, the Range Safety Officer (RSO) at the Cape Canaveral Air Force Station sent radio signals that activated the range safety system's "destruct" packages on board both solid rocket boosters. This was a normal contingency procedure, undertaken because the RSO judged the free-flying SRBs a possible threat to land or sea. The same destruct signal would have destroyed the External Tank had it not already disintegrated.[11]
    --
    When our name is on the back of your car, we're behind you all the way!
  3. Other abort modes! by pumpkinpuss · · Score: 5, Informative
    In addition to the destruct switch, there are other flight plans for an intact abort in case of problems. These abort modes are: Return to Landing Site (after SRBs are jettisoned, shuttle returns to Kennedy Space Center); East Coast Abort Landing where the orbiter lands on a different runway somewhere up the East Coast of the US; Transoceanic Abort Landing where the orbiter lands somewhere in Europe or Africa; Abort to Orbit; and Abort Once Around.

    The Solid Rocket Boosters can't be stopped once they are started, but they have their own navigation system (rate gyro assemblies, and inertial measurement units) that are considered as/more reliable as those on the orbiter due to the rigidity of the SRBs. So the reason this "self destruct" button exists is because there is no "off" button for the SRBs, but, as far as I know, it is only an issue if its quad-redundant navigation system fails and somehow its thrust gets stuck in an unsafe vector, and that is very unlikely.

    More detail, including why you can't jettison the flight deck with all the crewmembers: http://en.wikipedia.org/wiki/Space_Shuttle_abort_modes

  4. Technical details by Anonymous Coward · · Score: 5, Informative

    For the technical details on how this works, check out an old Risks article here. They put a lot of thought into the system.